Ion bombardment of alkali halides, V: Particle track effects

Abstract

Samples of nominally pure single crystal KCI were irradiated by H, H,, He, C and N positive ions in the energy range 0-2 MeV. The growth of F-type centers was recorded as a function of ion fluence. Depth profiles of damage by H and He ions were constructed, and it was found that the damage profile does not follow the stopping power as a function of penetration depth in the target. Determinations of damage track radii, based on the data, were done, and found to be on the order of 10 A. Comparisons of defect production by Hz with H at the same fluences of nuclei and the same energy per mass showed at low energies more defects by H than by H, , the difference attributable to track overlap.

Quantitative proton radiation therapy dosimetry using the storage phosphor europium‐doped potassium chloride

“…The infratrack is cylindrical, and is surrounded by a region of relatively low energy density, known as the particle “ultratrack.” The infratrack’s radius is determined by Bohr's adiabatic cutoff distance (ℏv/ΔE), where v refers to the relativistic velocity of the proton, ℏ refers to the Planck’s constant, and ΔE refers to the energy of the smallest allowed exciton (7.79 eV for KCl). For a 1‐MeV proton, this radius was calculated to be approximately 10 Å for KCl, which was experimentally confirmed in a later experiment 52 …”

“…For a 1-MeV proton, this radius was calculated to be approximately 10Å for KCl, which was experimentally confirmed in a later experiment. 52 LET-induced under-response in condensed media, such as KCl, can thus be explained by two main physical mechanisms. First, if the energy deposition within the infratrack by a single proton results in an immediate stage 1 Fcenter saturation, there will be a high possibility of LET effects.…”